The housing market can face a sudden drought in two to three years as state permits for new apartment constructions plunged more than 20 percent last year.

According to the Ministry of Land, Infrastructure and Transport on Tuesday, a total space of 38.53 million square meters had been granted for apartments last year, down 21.6 percent from 49.18 million square meters a year ago. The area in suburban cities and rural regions also was down more than 20 percent during the period, data showed.

Korea’s construction industry has enjoyed a boom driven by redevelopment and new offerings in Seoul and nearby areas. Approved land for apartments peaked at 60.71 million square meters in 2015 and then steadily slipped to 53.36 million square meters in 2016 and 49.18 million square meters in 2017.

The areas busy with apartment construction last year commanded 24 million square meters across the country last year, also down 23.1 percent. As construction takes two to three years, housing supplies may become lacking from 2021.

Meanwhile, the average return on leasing of residential buildings stood at 4.98 percent as of late last year, hovering below 5 percent for the first time since the data has been compiled in 2002.